Dr. Rupal Jain, and Dr. Amit Namdeo, Senior Research Fellow, AICRP on EAAI,
Dr. V.K. Bhargav, Project Coordinator, AICRP on EAAI,
ICAR-Central Institute of Agricultural Engineering, Bhopal (Madhya Pradesh)

Abstract:
Hydro-photovoltaic technology integrates solar panels on water surfaces such as lakes and reservoirs, optimizing land use and reducing water evaporation. It enhances energy efficiency and sustainability, addressing environmental challenges with potential for widespread adoption in renewable energy strategies.

Introduction
The widespread implementation of solar photovoltaic (PV) systems in certain regions may face limitations due to the amount of land required. This issue is particularly prominent in island nations or densely populated areas where sufficient land is not readily available for large-scale PV installations. Typically, PV systems occupy extensive land areas yet produce less energy compared to fossil fuel-based systems occupying similar land space. Moreover, conventional land-based solar projects during construction can pose various environmental concerns such as microclimate alterations, deforestation, soil erosion, biodiversity reduction and habitat loss. To address the challenges of land scarcity and mitigate environmental impacts, researchers and developers are actively seeking new alternatives for PV system installations. Recent developments indicate a growing inclination towards using current infrastructures for installing PV systems. Deploying PV systems on water surfaces like ponds, lakes, canals and reservoirs represents a strategic solution to the aforementioned challenges. This approach is innovative and represents a novel method of generating power. In dry/arid and semi-dry/semi-arid climates, water scarcity presents a significant challenge. By minimizing evaporation losses from water surfaces through PV installations, more water can be preserved for essential purposes. Covering water bodies with PV systems not only decreases evaporation but also mitigates algal growth, thereby maintaining water quality.

A research team has highlighted the installation of floating PV systems on tranquil water bodies such as dams, lakes, ponds, and reservoirs (Fig. 1). These floating solar plants achieve an efficiency that is 11% higher and reduce water evaporation by 70%. However, the initial investment for such power plants is 1.2 times greater than that of conventional solar power plants.

Fig. 1- Solar Photovoltaic System on water bodies


Key benefits:

1. The primary objective of this technology is to minimize water loss through evaporation from natural water bodies.

2. It aims to circumvent the necessity for land typically required for traditional PV installations.

3. Additionally, it seeks to mitigate adverse environmental effects such as deforestation, habitat loss, biodiversity depletion, alterations in microclimates, and soil erosion.

4. This approach harnesses substantial solar energy potential using PV technology without relying on land resources, leveraging India's abundant availability of large water bodies.

Implementation of technology:
The Madhya Pradesh government is establishing a substantial 1000 MW floating solar power plant on the Indira Sagar Dam in Khandwa district. This ambitious project aims to harness renewable energy from the state's abundant water resources. Estimated at Rs 5 crore per megawatt, the plant will utilize a floating platform on the reservoir, eliminating the need for extensive land acquisition typically required for conventional solar installations. This innovative approach not only reduces environmental impact but also optimizes land use, marking a significant step towards sustainable energy generation in the region. By leveraging the vast expanse of the reservoir, the government seeks to bolster its capacity for green energy production, aligning with broader efforts to enhance renewable energy infrastructure across Madhya Pradesh.

The solar plant under construction in Khandwa district is recognized as the largest floating solar plant globally. It incorporates specialized technology akin to a hydropower plant to harness electricity from water, alongside traditional solar panels installed on the water surface to generate power.

Conclusions:
Hydrophotovoltaic technology represents a transformative approach to renewable energy deployment, particularly in regions where land scarcity and environmental concerns pose significant challenges. By utilizing water surfaces such as lakes, ponds, and reservoirs for PV installations, this innovation not only conserves land but also reduces water evaporation rates, thereby addressing water scarcity issues in arid and semi-arid climates. The environmental benefits are notable, as hydrophotovoltaic installations help preserve natural habitats and biodiversity by minimizing the need for land-based solar farms that can lead to deforestation and habitat destruction. As the technology matures and becomes more economically viable despite initial higher investment costs, its adoption promises to contribute significantly to global efforts in combating climate change and advancing sustainable development goals. Embracing hydrophotovoltaic technology represents a promising step towards achieving a cleaner and more resilient energy future.